When Dewey is dancing with Mrs. White, the rose she has appears and disappears frequently.
Dewey and Mrs White are in a 'tent' and eating cookies. Dewey's cookie has fewer bites out of it at the end of the scene.
Hal & Lois are in the water. Malcolm complains about Reese and Lois tells him to deal with it. As he turns and walks away, he removes the nose plug. A second later he removes it again as he approaches Reese.
Malcolm pushes Lois down the Liquidator. Viewed from in chute, the boys are not touching. Viewed from the side, Reese's hand is on Malcolm's shoulder.
The shape of Dewey's chocolate moustache changes during the ABBA Fernando dance.
In the first scene after the opening credits, when Hal is getting his back shaved, The feet, legs, and right sides of two crew members are visible on the right of the screen.